United States
Identification
Title of the survey: Current Population Survey (CPS)
Organisation responsible: U.S. Census Bureau
Objectives of the survey: Collect timely labour force information.
Date: 09/06/2011
Periodicity and coverage
Periodicity of data collection: Monthly
Geographical coverage: Whole country
Population coverage: Whole population excluding the following groups: Armed forces,
persons living in institutions and homeless people
Definition of usual resident: The usual place of residence is defined as the place where a
person usually lives and sleeps. It must be specific living quarters held by the person to which
he/she is free to return at any time. Living quarters rented or loaned to someone else or that
are exchanged for other living quarters temporarily, cannot be considered as a usual place of
residence during the time these quarters are occupied by someone else.
Definition of household and household members: The following persons in a sample unit
are considered as household members: 1) Persons, whether present or temporarily absent,
whose usual place of residence at the time of interview is the sample unit. 2) Persons staying
in the sample unit who have no usual place of residence elsewhere. A household is defined
as all individuals (related family members and all unrelated individuals) whose usual place of
residence at the time of the interview is the sample unit. Individuals who are temporarily
absent and who have no other usual address are still classified as household members even
though they are not present in the household during the survey week. College students
compose the bulk of such absent household members, but people away on business or
vacation are also included. (Not included are individuals in institutions or the military.) Once
household/non household membership has been established for all people on the roster, the
interviewer proceeds to collect all other demographic data for household members only. The
unit of observation is a household address, not people. The CPS does not follow people if or
when they move, but covers whoever is currently in the household (address). The CPS is not
limited to U.S. citizens. It includes foreign citizens residing in the U.S. who are not living in
embassies. Please refer to Chapter 5 of CPS Technical Paper 66:
http://www.census.gov/prod/2006pubs/tp-66.pdf
Usual household members who are temporarily absent are enumerated in the survey:
Yes, in household roster only
Age coverage: The labour related questions of the survey relate to the population of 16 years
old and over
Topics covered:
Demographic characteristics: age, sex, marital status, place/country of birth, ethnicity,
educational attainment, relationship to household head, disability
Main labour related characteristics: employment, unemployment, underemployment, hours
of work, wages, employment related benefits, trade union affiliations, voluntary work,
absence from work
Other labour related characteristics: industry, occupation, institutional sector
(public/private), size of establishment, full time/part time status, permanency of the job,
working time arrangements, duration of employment, existence of more than one job,
characteristics of the second job(s), duration of unemployment, previous working experience,
characteristics of the last job, search for another job, methods of looking for work, receipt of
unemployment benefits, reasons for not being in the labour force
Other characteristics: other sources of income (e.g. income from property)
Concepts and definitions
Current employment
Definition of employment: Employed persons are those who are working at a paid job or
business for at least one hour during the reference week, or are working without pay in a
family business for 15 or more hours during the reference week or who did not work that
week, but held a job or owned a business from which they were temporarily absent.
Employment refers to people who during the reference period:
- worked for one hour or more for wage or salary, in cash or in kind
- worked for at least 15 hours without pay on a family business or farm
Reference period for employment: The week containing the 12th of the month (fixed)
Comments: Sometimes the week of the 5th in November and December
Current unemployment
Definition of unemployment: The unemployed are persons who had no employment during
the reference week, were available for work at that time except for temporary illness, and had
made active efforts to find employment sometime during the 4-week period ending with the
reference week. Persons who were waiting to be recalled to a job from which they had been
laid off need not be actively looking to be classified as unemployed.
Unemployment refers to people who during the reference period: Are without work,
available to work and actively seeking work
Reference period for seeking work: The four weeks preceding the interview date (moving)
Reference period for availability for work: The week containing the 12th of the month
(fixed)
Comments: Sometimes the week of the 5th in November and December
Underemployment
Underemployment concept measured: Time related underemployment
Definition of underemployment related to working time: Underemployment refers to
those who worked part time for economic reasons, that is, people who wanted a full time job
but worked less than 35 hours during the reference week for reasons such as slack work or
the inability to find full-time work. There are two categories of part time for economic
reasons: those who usually work full time and those who usually work part time (based on
usual hours). The number of hours they worked during the reference week is based on actual
hours.
Underemployment refers to employed persons who:
- worked less than 35 hours a week in all jobs
- want to work additional hours
Information collected on the number of hours of work wanted/ available for: No
Hours of work
The survey measures: hours actually worked and usual hours
Information is collected for: main and secondary job(s) separately
Reference period used for the measure of hours of work: a week
Actual hours of work are collected for: the week as a whole
Separate information is collected for overtime hours: yes
Definition of overtime hours: The CPS captures usual hours and actual hours at work. Fulltime workers are those who usually work 35 hours or more per week. Part-time workers are
those who usually work less than 35 hours per week (whether for economic reasons or for
noneconomic reasons). We do not collect information in the CPS on overtime hours per se.
The question is "(THE WEEK BEFORE LAST/LAST WEEK), did (name/you) work any
overtime or extra hours (at (his/her) MAIN job that / that)(you/he/she) (do/does) not usually
work?" This lumps together "overtime" and "extra hours."
Separate information is collected for absence hours: yes
Definition of absence hours: Hours lost or taken off compared to usual hours of work.
Separate information is collected for working time arrangements: no
Time unit used in the measure of hours of work: exact hours
Income from paid employment
The components of income for which separate statistics are available are: regular cash
earnings, irregular cash earnings, profit related pay, College assistance
Income from paid employment covered: GROSS income
Reference period: no reference period - usual earnings are collected
Income from paid employment refers to: main job only
Information on income from paid employment is requested in: exact amounts
Comments: Data on usual weekly earnings received is collected. Weekly is not a reference
period. Responses above refer to usual weekly earnings collected in the monthly Current
Population Survey.
Income from self-employment
Employment in the informal sector
Informal employment
Usual activity
Treatment of special groups
- Persons with a job but temporarily absent due to parental leave are classified as employed
- Persons with a job but temporarily absent due to educational or training leave are classified
as employed
- Persons with a job but temporarily absent due to voluntary leave without pay are classified
as employed
- Persons on temporary lay-off without pay are classified as unemployed if they expect to be
called back to work
- Persons without work and currently available for work who are not seeking work during the
reference period due to specific reasons (e.g. discouraged workers) are classified as
economically inactive
- Persons who performed some work for pay or profit during the reference period but were
subject to compulsory schooling are classified as employed
- Persons who performed some work for pay or profit during the reference period but were
full-time or part-time students are classified as employed
- Persons who performed some work for pay or profit during the reference period but were
retired and/or receiving a pension are classified as employed
- Persons who performed some work for pay or profit during the reference period but were
registered as jobseekers at an employment office are classified as employed
- Persons who performed some work for pay or profit during the reference period but were
receiving unemployment benefits are classified as employed
- Paid apprentices and trainees are classified as employed
Classifications
Disaggregations used in the analysis and tabulation of the survey results:
- The economically active population is tabulated by:
- The employed population is tabulated by: sex, age, industry, occupation, level of education,
institutional sector (public/private), urban/rural area
- The unemployed population is tabulated by: sex, age, industry, occupation, level of
education, institutional sector (public/private), urban/rural area
- The economically inactive population is tabulated by:
Classifications used
Industry:
- Title of the classification: Census industry coding system (NAICS based)
- Number of most detailed groups or digits used: 256 groups
Occupation:
- Title of the classification: Census occupation coding system (SOC based)
- Number of most detailed groups or digits used: 535 groups
Status in employment:
Education:
- Title of the classification: PEEDUCA
Sample design
Sampling frame: Master address file based on Decennial Census
The sampling frame is updated: continually
Procedure used to update the sampling frame: The sample is updated continuously for
new housing built after Census 2000.
Lowest level of geographic disaggregation for which reliable estimates of the
unemployment rate can be produced and their frequency: Cities with 25000 inhabitants
and over (monthly)
The sample is stratified: Yes
Variables used for stratification: geographic region, urbanisation, population size of
locality, socio-economic characteristics: labour force characteristics and other characteristics
that are highly correlated with unemployment
Number of sampling stages: 2
Ultimate sampling units: dwellings
Sample size: 60000 ultimate sampling units per month
Sample fraction: 0.055% of the total population
Sample rotation takes place: at the ultimate sampling unit level only
The rotation system results in: the overlap between consecutive survey periods and the
overlap between same periods one year apart
Percentage of ultimate sampling units remaining in the sample for two consecutive
survey rounds: 75%
Maximum number of times an ultimate sampling unit is interviewed: 8
Months needed to renew the sample completely: 16
Data collection
Main mode of data collection: computer assisted personal interview (CAPl)
The field staff is mainly: part of a permanent survey organisation
Duration of training on the survey for newly recruited interviewers: 5 day(s)
Respondents' participation in the survey is compulsory: No
Ultimate sampling units that could not be identified are replaced: No
Ultimate sampling units that could not be contacted are replaced: No
Ultimate sampling units that refuse to participate are replaced: No
Estimation and adjustment
Percentage of all eligible ultimate sampling units that are interviewed: 92%
Percentage of refusals in the total non-response: 17%
The sample is self-weighting: No
Weighting factors used to adjust for: sample design, survey non-response, bench-marking
(to ensure consistency between survey estimates and those from other reliable source(s), e.g.
census)
Adjustment for item non-response is made: Yes
Method of imputation: The three imputation methods used by the CPS edits are: (1)
Relational imputation infers the missing value from other characteristics on the person’s
record or within the household. For instance, if race is missing, it is assigned based on the
race of another household member, or failing that, taken from the previous record on the file.
Similarly, if relationship data is missing, it is assigned by looking at the age and sex of the
person in conjunction with the known relationship of other household members. Missing
occupation codes are sometimes assigned by analyzing the industry codes and vice versa.
This technique is used as appropriate across all edits. If missing values cannot be assigned
using this technique, they are assigned using one of the two following methods.(2)
Longitudinal edits are used in most of the labour force edits, as appropriate. If a question is
blank and the individual is in the second or later month’s interview, the edit procedure looks
at last month’s data to determine whether there was an entry for that item. If so, last month’s
entry is assigned; otherwise, the item is assigned a value using the appropriate hot deck, as
described next. (3) The third imputation method is commonly referred to as ‘‘hot deck’’
allocation. This method assigns a missing value from a record with similar characteristics,
which is the hot deck. Hot decks are defined by variables such as age, race, and sex. Other
characteristics used in hot decks vary depending on the nature of the unanswered question.
For instance, most labour force questions use age, race, sex, and occasionally another
correlated labour force item such as full- or part-time status. This means the number of cells
in labour force hot decks are relatively small, perhaps fewer than 100. On the other hand, the
weekly earnings hot deck is defined by age, race, sex, usual hours, occupation, and
educational attainment. This hot deck has several thousand cells.
Relative standard errors computed:
- Total unemployment rate: 0.2 %
Confidence level: 90 %
If sub-annual surveys are conducted, the results are adjusted for seasonal variations:
Yes
Data series seasonally adjusted: 1060 seasonally adjusted series
ftp://ftp.bls.gov/pub/time.series/ln/ln.series and ftp://ftp.bls.gov/pub/time.series/le/le.series
Method(s) used for seasonal adjustment: X-12 ARIMA
Selected indicators tabulated from the survey:
- Unemployment rate by: sex, age, level of education, occupation, region (urban/rural)
- Employment to population ratio by: sex, age, level of education, occupation, region
(urban/rural)
- Labour force participation rate by: sex, age, level of education, occupation, region
(urban/rural)
- Hours of work (per worker) by: sex, age, level of education, occupation, region
(urban/rural)
- Earnings (per worker) by: sex, age, level of education, occupation, region (urban/rural)
- Number of workers by hours band by: sex, age, level of education, occupation, region
(urban/rural)
- Number of workers by earnings class by: sex, age, level of education, occupation, region
(urban/rural)
Availability of data from other sources
- Data on employment is also available from: establishment surveys and administrative
records
- Data on hours of work is also available from: establishment surveys
- Data on wages is also available from: establishment surveys and administrative records
LFS data are considered official for:
- employment: yes
- unemployment: yes
- earnings: yes
- hours of work: yes
Documentation and dissemination
Publication(s) and website where the survey results can be found: Employment Situation
news release; many annual publications; www.bls.gov/cps
Publication(s) and website where methodological information on the survey can be
found: Design and Methodology: Current Population Survey, Technical Paper 66;
www.census.gov/prod/2006pubs/tp-66.pdf
Dissemination formats and periodicity:
- news release (monthly)
- comprehensive report (monthly)
- online database (monthly)
- microdata access (monthly)
Time needed for an initial release of the survey results: approximately 2 weeks after the
end of the data collection period
The public is informed in advance on the date of the initial release of survey results: Yes
Non-published results can be made available on request: Yes
Micro data are made available on request: Yes
Comments: Not revised on a monthly basis
Historical information
Year when the survey was conducted for the first time: 1940
Years when significant methodological changes were introduced: Chapter 2 of the
Technical paper 66 on the Current Population Survey gives the details regarding
methodological changes over time. Available at: http://www.census.gov/prod/2006pubs/tp66.pdf